• RabbitMQ学习笔记

    RabbitMQ学习笔记

    1、为什么会产生消息队列（MQ）？

    不同进程之间相互通信时，两者如果耦合度过高，改动一个进程则另一个进程也必须改动。为了降低两个进程的耦合度，于是抽离出来一个模块，用来管理两个进程相互通信的消息。

    更多详细介绍请参阅

    1、《Java帝国之消息队列》

    2、《一个故事告诉你什么是消息队列》

    3、《到底什么时候该使用MQ》

    2、设置虚拟主机

    1、新建一个虚拟主机（每个虚拟主机相当于MySql中的每个数据库）QQ截图20191022162020

    2、将登录用户添加到虚拟主机（下图中，guest用户没有添加，则guest用户没有访问/lxy这个虚拟主机的权限）

    QQ截图20191022162118

    测试：

    新建一个Test类

    @Test
    public void test1(){
        rabbitTemplate.convertAndSend("exchange.direct","lixingyu1",new Person(1,"Rlxy93",21,"重庆"));
        System.out.println("发送消息成功！");
    }

    QQ截图20191022162452

    QQ截图20191022162441

    如果是guest用户（报错，因为guest用户没有访问指定虚拟路径的权限）：

    org.springframework.amqp.AmqpIOException: java.io.IOException

	at org.springframework.amqp.rabbit.support.RabbitExceptionTranslator.convertRabbitAccessException(RabbitExceptionTranslator.java:71)
	at org.springframework.amqp.rabbit.connection.AbstractConnectionFactory.createBareConnection(AbstractConnectionFactory.java:510)
	at org.springframework.amqp.rabbit.connection.CachingConnectionFactory.createConnection(CachingConnectionFactory.java:751)
	at org.springframework.amqp.rabbit.connection.ConnectionFactoryUtils.createConnection(ConnectionFactoryUtils.java:214)
	at org.springframework.amqp.rabbit.core.RabbitTemplate.doExecute(RabbitTemplate.java:2092)
	at org.springframework.amqp.rabbit.core.RabbitTemplate.execute(RabbitTemplate.java:2065)
	at org.springframework.amqp.rabbit.core.RabbitTemplate.send(RabbitTemplate.java:1004)
	at org.springframework.amqp.rabbit.core.RabbitTemplate.convertAndSend(RabbitTemplate.java:1070)
	at org.springframework.amqp.rabbit.core.RabbitTemplate.convertAndSend(RabbitTemplate.java:1063)
	at cn.lixingyu.springadvanced.RabbitPractice.test1(RabbitPractice.java:31)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:74)
	at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:84)
	at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
	at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
	at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.io.IOException
	at com.rabbitmq.client.impl.AMQChannel.wrap(AMQChannel.java:129)
	at com.rabbitmq.client.impl.AMQChannel.wrap(AMQChannel.java:125)
	at com.rabbitmq.client.impl.AMQChannel.exnWrappingRpc(AMQChannel.java:147)
	at com.rabbitmq.client.impl.AMQConnection.start(AMQConnection.java:403)
	at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:1115)
	at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:1063)
	at org.springframework.amqp.rabbit.connection.AbstractConnectionFactory.connect(AbstractConnectionFactory.java:526)
	at org.springframework.amqp.rabbit.connection.AbstractConnectionFactory.createBareConnection(AbstractConnectionFactory.java:473)
	... 38 more
Caused by: com.rabbitmq.client.ShutdownSignalException: connection error; protocol method: #method<connection.close>(reply-code=530, reply-text=NOT_ALLOWED - access to vhost '/lxy' refused for user 'guest', class-id=10, method-id=40)
	at com.rabbitmq.utility.ValueOrException.getValue(ValueOrException.java:66)
	at com.rabbitmq.utility.BlockingValueOrException.uninterruptibleGetValue(BlockingValueOrException.java:36)
	at com.rabbitmq.client.impl.AMQChannel$BlockingRpcContinuation.getReply(AMQChannel.java:502)
	at com.rabbitmq.client.impl.AMQChannel.privateRpc(AMQChannel.java:293)
	at com.rabbitmq.client.impl.AMQChannel.exnWrappingRpc(AMQChannel.java:141)
	... 43 more

    3、RabbitMQ的5种模式

    生产者/消费者模式

    新建一个Test类

    package cn.lixingyu.springadvanced;

import cn.lixingyu.springadvanced.entity.Person;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.amqp.core.AmqpAdmin;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

/**
 * @author Rlxy93
 * @time 2019/10/21 18:02
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class RabbitPractice {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    @Test
    public void test1(){
        //发送
        rabbitTemplate.convertAndSend("exchange.direct","lixingyu1",new Person(1,"Rlxy93",21,"重庆"));
        System.out.println("发送成功！");
        //接收
        Object lixingyu1 = rabbitTemplate.receiveAndConvert("lixingyu1");
        System.out.println(lixingyu1.getClass());
        System.out.println((Person)lixingyu1);
        System.out.println("接收成功！");
    }
}

    运行效果：

    QQ截图20191022163531

    Work模式

    private final String QUEUE_NAME = "Rlxy93";

    @Test
    public void test1(){
        for (int i = 0;i<10;++i){
            rabbitTemplate.convertAndSend("exchange.direct",QUEUE_NAME,new Person(i,"Rlxy93",21,"重庆"));
            System.out.println("发送成功！"+i);
        }
    }

    @RabbitListener(queues = QUEUE_NAME)
    public void rabbitListener1(Person p){
        System.out.println("rabbitListener1接收成功！");
        System.out.println(p);
    }

    @RabbitListener(queues = QUEUE_NAME)
    public void rabbitListener2(Person p){
        System.out.println("rabbitListener2接收成功！");
        System.out.println(p);
    }

    运行结果：

    QQ截图20191022165556

    ps：

    ​ 1、两个listener接收到的消息是不同的。

    ​ 2、两个listener貌似是有规律的接收的。

    ​ 3、两个listener接收到的消息数量是相同的。

    其中就牵扯到轮询（round-robin）分发消息的概念。

    轮询分发：在默认情况下，RabbitMQ将逐个发送消息到在序列中的下一个消费者(而不考虑每个任务的时长等等，且是提前一次性分配，并非一个一个分配)。平均每个消费者获得相同数量的消息。这种方式分发消息机制称为Round-Robin（轮询）。

    轮询分发暴露出来的弊端：比如：现在有2个消费者，所有的奇数的消息都是繁忙的，而偶数则是轻松的。按照轮询的方式，奇数的任务交给了第一个消费者，所以一直在忙个不停。偶数的任务交给另一个消费者，则立即完成任务，然后闲得不行。

    于是有了公平分发：

    在application.properties中加

    #设置同一时刻服务器只会发1条消息给消费者
spring.rabbitmq.listener.simple.prefetch=1

    测试代码：

    package cn.lixingyu.springadvanced;

import cn.lixingyu.springadvanced.entity.Person;
import com.rabbitmq.client.Channel;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.support.AmqpHeaders;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.messaging.handler.annotation.Header;
import org.springframework.test.context.junit4.SpringRunner;

import java.io.IOException;

/**
 * @author Rlxy93
 * @time 2019/10/21 18:02
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class RabbitPractice {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    private final String QUEUE_NAME = "Rlxy93";

    @Test
    public void test1() {
        for (int i = 0; i < 16; ++i) {
            rabbitTemplate.convertAndSend("Rlxy93", QUEUE_NAME, new Person(i, "Rlxy93", 21, "重庆"));
        }
    }

    @RabbitListener(queues = QUEUE_NAME)
    @RabbitHandler
    public void rabbitListener1(Person p, Channel channel, @Header(AmqpHeaders.DELIVERY_TAG) long tag) throws InterruptedException, IOException {
        Thread.sleep(500);
        System.out.println("RabbitMQListener1接收成功！" + p);
    }

    @RabbitListener(queues = QUEUE_NAME)
    @RabbitHandler
    public void rabbitListener2(Person p, Channel channel, @Header(AmqpHeaders.DELIVERY_TAG) long tag) throws InterruptedException, IOException {
        System.out.println("RabbitMQListener2接收成功！" + p);
    }

}

    运行效果：

    QQ截图20191022224153

    订阅模式

    学习地址：springboot整合rabbitmq的五种模式示例

    广播模式

    1、首先新建一个exchange，名叫Rlxy93.fanout，把模式改成fanout。

    2、再在Queue中，新建两个和@RabbitListener里@Queue的名字一样的两个Queue，分别把Rlxy93.fanout给绑定上。

    代码

    package cn.lixingyu.springadvanced;

import cn.lixingyu.springadvanced.entity.Person;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.amqp.core.ExchangeTypes;
import org.springframework.amqp.rabbit.annotation.Exchange;
import org.springframework.amqp.rabbit.annotation.Queue;
import org.springframework.amqp.rabbit.annotation.QueueBinding;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

/**
 * @author Rlxy93
 * @time 2019/10/22 22:54
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class FanoutPractice {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    private final String EXCHANGE = "Rlxy93.fanout";

    @Test
    public void test() {
        for (int i = 0; i < 1; ++i) {
            rabbitTemplate.convertAndSend(EXCHANGE, "", new Person(i, "Rlxy93", 21, "重庆"));
        }
    }

    @RabbitListener(bindings = @QueueBinding(value = @Queue(value = "Rlxy93", durable = "true"),
            exchange = @Exchange(value = EXCHANGE,type = ExchangeTypes.FANOUT)))
    public void rabbitListener1(Person p) {
        System.out.println("RabbitMQListener1..." + p);
    }
    @RabbitListener(bindings = @QueueBinding(value = @Queue(value = "Rlxy931", durable = "true"),
            exchange = @Exchange(value = EXCHANGE,type = ExchangeTypes.FANOUT)))
    public void rabbitListener2(Person p) {
        System.out.println("RabbitMQListener2..." + p);
    }
}

    运行效果：

    QQ截图20191022232223

    路由模式

    新建一个类：

    package cn.lixingyu.springadvanced;

import cn.lixingyu.springadvanced.entity.Person;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.amqp.core.ExchangeTypes;
import org.springframework.amqp.rabbit.annotation.Exchange;
import org.springframework.amqp.rabbit.annotation.Queue;
import org.springframework.amqp.rabbit.annotation.QueueBinding;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

/**
 * @author Rlxy93
 * @time 2019/10/22 23:29
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class DirectPractice {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    private final String EXCHANGE = "Rlxy93.direct";

    @Test
    public void test() {
        for (int i = 0; i < 1; ++i) {
            rabbitTemplate.convertAndSend(EXCHANGE, "lxxxxxxy", new Person(i, "Rlxy93", 21, "重庆"));
        }
    }

    @RabbitListener(bindings = @QueueBinding(value = @Queue(value = "Rlxy93", durable = "true"),
            exchange = @Exchange(value = EXCHANGE,type = ExchangeTypes.DIRECT), key = {"lxxxxxxy"}))
    public void rabbitListener1(Person p) {
        System.out.println("RabbitMQListener1..." + p);
    }

    @RabbitListener(bindings = @QueueBinding(value = @Queue(value = "Rlxy93"),
            exchange = @Exchange(value = EXCHANGE,type = ExchangeTypes.DIRECT), key = {"direct"}))
    public void rabbitListener2(Person p) {
        System.out.println("RabbitMQListener2..." + p);
    }
}

    运行效果：

    QQ截图20191023001429

    ps：

    ​ 1、如果监听的两个Queue名称相同，则寻找key值对应的，如果没有找到对应的key值，则返回空。

    ​ Queue相同，找到对应key值。

    QQ图片20191023002045

    ​ Queue相同，没有对应key值，返回空。

    QQ截图20191023002206

    ​ 2、如果监听的两个Queue名称不同，则直接找存在key值的Queue，不再找对应的key值，如果不存在带有相同key值的Queue，则返回空。

    ​ Queue不同，找存在的对应的key值。

    QQ截图20191023002531

    ​ Queue不同，找不存在的key值，返回空。

    QQ截图20191023002712

    ​ 3、如果监听的两个Queue名称相同，在RabbitMQ中两个都有对应的key，则把两个都返回。

    ​ Queue相同，key也相同，两个都能找到。

    QQ截图20191023002914

    Topic（主题模式）

    首先在RabbitMQ中绑定两个Queue

    QQ截图20191023083113

    QQ截图20191023083101

    新建一个类

    package cn.lixingyu.springadvanced;

import cn.lixingyu.springadvanced.entity.Person;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.amqp.core.ExchangeTypes;
import org.springframework.amqp.rabbit.annotation.Exchange;
import org.springframework.amqp.rabbit.annotation.Queue;
import org.springframework.amqp.rabbit.annotation.QueueBinding;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

/**
 * @author Rlxy93
 * @time 2019/10/23 08:23
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class TopicPractice {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    private final String TOPIC = "Rlxy93.topic";

    @Test
    public void test() {
        for (int i = 0; i < 1; ++i) {
            rabbitTemplate.convertAndSend(TOPIC, "Insert.Rlxy93", new Person(i, "Insert.Rlxy93", 21, "重庆"));
            rabbitTemplate.convertAndSend(TOPIC, "Delete.Rlxy93", new Person(i, "Delete.Rlxy93", 21, "重庆"));
            rabbitTemplate.convertAndSend(TOPIC, "Delete.Rlxy93", new Person(i, "Delete.Rlxy93", 21, "重庆"));
        }
    }

    @RabbitListener(bindings = @QueueBinding(value = @Queue(value = "Rlxy93", durable = "true"),
            exchange = @Exchange(value = TOPIC, type = ExchangeTypes.TOPIC), key = {"Insert.*"}))
    public void rabbitListener1(Person p) {
        System.out.println("RabbitMQListener1..." + p);
    }

    @RabbitListener(bindings = @QueueBinding(value = @Queue(value = "Rlxy931", durable = "true"),
            exchange = @Exchange(value = TOPIC, type = ExchangeTypes.TOPIC), key = {"Delete.*"}))
    public void rabbitListener2(Person p) {
        System.out.println("RabbitMQListener2..." + p);
    }

}

    运行结果：

    QQ截图20191023083245

    ps：Topic主题模式可以根据通配符来绑定不同的消息。
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  • 原文地址：https://www.cnblogs.com/lxxxxxxy/p/11880142.html
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